Buying privilege? Private education, such as that offered at Eton (pictured), has opened up opportunities for the middle classes (photo: Graeme Robertson/Getty Images)

Even those who wish to express their dislike for public schools are well aware that they have played and continue to play an important role in national life. After all, the number of times that the newspapers tell us that David Cameron and Boris Johnson attended Eton or that George Osborne attended St Paul’s is beyond counting. Racial prejudice is rightly condemned, along with gender discrimination and discrimination on the grounds of sexual orientation. But dismissing someone as a product of a public school — that is perfectly acceptable. The reverse side of this coin is the way one journalist after another proudly confesses to a grammar school education, even though several of these grammar schools, notably in Manchester, have often been classed along with the public schools as members of the Headmasters’ Conference. It makes sense, then, to ask what a public school is. A breezy and at the same time sensible guide to this problem has been provided by a new book published by Yale University Press entitled The Old Boys: The Decline and Rise of the Public School (£25), in which David Turner shows how the public schools continue to make a much more positive contribution to British society than many would care to admit.

First, then, the definition. In 1861 the Clarendon Commission identified nine old schools that were thought to qualify, including Charterhouse, Rugby, St Paul’s and the very wealthy foundation of Merchant Taylors’. The public schools, as the term betrays, came into being as schools that in some way served the nation, as the three great collegiate schools at Winchester, Eton and Westminster have done for many centuries. David Turner lays much emphasis on the role played by the first school to have been imbued from the start with the humanist principles of the Northern Renaissance, St Paul’s, founded by John Colet in around 1509. It was national because it served the elite of the national capital (if parents could not pay the cost of wax candles to be taken to school every day, their children would not be welcome — no cheap, smelly, vulgar tallow here!); and at various points in its history it was favoured by the high-born as well as by the professional classes, without ever having large numbers of boarders.

Their patronage by professional parents is, as Turner shows, the most interesting thing about these schools, even about Eton and Harrow: far from cultivating an exclusive poshness, there has always been space for those whose less grand parents sought advancement for their children. They have been a ladder for social ascent even when the quality of education they have offered has left something to be desired. Admittedly, they have been expensive, and are becoming more so as the facilities they offer are transformed into those of five-star hotels. There have never been enough scholarships, and to win one of those it helps to have been educated first at a very good prep school, which itself will be costly, so breaking into the system has never been easy. This problem has become more acute as middle-class parents find themselves without the means to pay the fees demanded, and the schools themselves have become increasingly reliant on foreign students, from China, Russia and elsewhere.